Method for stereoscopic scanning of pictures



April 15, 1941.

J. z. DENINSON METHOD FOR STEREOSCOPIC SCANNING 0F PICTURES Filed April24, 1957 2 Sheets-Sheet l April 1941- J. z. DENINSON 2,238,629

METHOD FOR STEREOSCOPiC SCANNING OF PICTURES Filed April 24,1937 2Sheets-Shet 2 I V EN TOR.

A TTORNEYS.

1m mil/M Patented Apr. 15, 1941 METHOD FOR STEREOSCOPIC SCANNING I OFPICTURES Jacob Z. Deninson, New York, N. Y.

Application April 24, 1937, Serial No. 138,767

2 Claims. (01. 8816.6)

My invention relates to a new and improved device for producingstereoscopic projection from special transparencies or special film. Theinvention also relates to a method of securing monostereoscopicprojection from film which has been specially prepared.

Another object of my invention is to utilize a series of prisms, orcylinders, or other corresponding optical members, between which and thediapositive or film there is relative movement, while the diapositive orfilm is being projected upon a suitable screen.

Another object of my invention is to provide a method whereby motionpicture film can be fed intermittently through a projector in the usualmanner, and while each frame of the film is being maintained stationaryfor a fraction of a second, the light which passes to the objectivelenssystem, is caused to pass through a series of suitable optical memberswhich are preferably of the retracting type.

A relative movement is produced between the frame and said opticalmembers, preferably by moving the optical members at suitable speedrelative to the frame, while said frame is maintained stationary.

Another object of my invention is to utilize optical members or opticalmeans, either of the refracting type or reflecting type, whereby thelight which is projected upon the screen is divided into a series ofsections of varying brightness, although the optical parts may beadjusted so as to give the effect of substantially uniform illuminationover the entire screen. By causing a. relative movement between theoptical members or the optical means, and the frame or picture which isbeing viewed, and while projecting said frame or picture upon thescreen, the eflect of monostereoscopic vision is secured.

Another object of my invention is to utilize th properties of cylinders,prisms, or other equivalent optical means or optical el ents.

While I prefer to locate the ttery of cylinders or other refractingelements, between the source of light and the transparency which isbeing projected, I have also shown, in other embodiments of myinvention, the location of the cylinders or other refracting means,between the transparency and the projecting-lens system. In

such case I may use prisms and two projectinglens systems, in order toroduce a single image upon thescreen of each line element, although I donot limit myself to the use of prisms or a plurality of rojecting lenssystem.

While my invention relates to the projection of a transparency or film,it also relates to the use of the same optical principles, in takingmotion pictures or other pictures, although, as

previously stated, I prefer to take the pictures or motion pictures bymeans of a conventional camera, and without using the cylinders orsimilar accessory optical means.

There are numerous other objects of my invention, which will be statedfurther in the following description and drawings, which illustratecertain preferred embodiments thereof, in diagrammatic form.

Fig. 1 is a plan view, illustrating two frames which are separatepictures of the same object in the same position, taken by the twolenses of a stereoscopic camera. One of said frames has been takenthrough one lens, and the other frame through the other lens. Each ofthese frames corresponds in size to the conventional gate which may beused in the ordinary motionpicture projection apparatus. For exampleeach of these frames may have a width of one inch and a height of of aninch. Of course these frames respectively correspond'to left-eye and toright-eye images of the same object in the same position.

Fig. 2 represents the respective frames of Fig. 1, showing how eachframe has been reduced alon a single dimension, namely, the height ofthe frame. In this embodiment, the width of the frame has beenmaintained constant and the height of the film has been reduced toone-half of its original height. Fig. 2 also shows how each reducedframe can be assumed as having been divided optically into, any desirednumber of lateral zones or lateral sections, four sections being shownin this embodiment, merely for convenience of illustration. In actualpractice the number of lateral sections would be much greater.

It is to be understood that whenever any specific figures or proportionsare referred to, this is only by way of example, and is not alimitation.

Fig. 3 shows the type of film which may be used in the actual projectionmachine. This film consists of successive lateral sections, andeaclipair of consecutive lateral sections corresponds to correspondinglateral sections of the respective reduced frames shown in Fi 2.

Fig. 4 is a diagrammatic view illustrating how one of the lateralsections 21 shown in Fig. 3 is magnified, if a cylinder A is placed infront of said section if, and the strip 2} is viewed through saidcylinder.

the frames illustrated in Fig. i.

Fig. is a side-view of Fig. '2.

Re. 7 shows an assembled series of cylinders, in each of which thediameter of the circular end face of the cylinder is much greater thanthe length oi the cylinder, as measured in a direction parallel to thelongitudinal axis of the cylinder. 1? 7 also includes a double headedarrow, in order to indicate that the battery of cylinders is moved in adirection parallel to the longitudinal axes of said cylinders, since theaxes of all the cylinders are parallel to each other. Fig. 7 also showsthe frame Fig. 7 also indicates that the cylinders are assembled so thattheir central points are along a straight line which is inclined to theaxes.

Fig. 8 is a side elevation showing a different embodiment of theinvention. This illustrates a battery of cylinders which are suitablyconnected to each other, and which are arranged with their axeshorizontal and superposed and in the same vertical plane. In thisembodiment the length of each cylinder is much greater than the diameterof the end wall of the cylinder.

Fig. 8a is a front elevation of .c'g. 8.

The double headed arrows in r 'g. 8 and Fig. 8a indicate the line alongwhich the cylinders are reciprocated. v

9 is similar to 8, save that in Fig. t the cylinders are reciprccated ina direction parallel to the long or horizontal edge of the frame,whereas in 8, the cylinders are reciprocaterl vertically andperpendicular to the long edge of the frame.

9a is a front elevation of Fig. 9.

ii) is an elevation of the frame or" a roelion. picture film which isprojected by intermit tent movement in a direction parallel to itslength and shows series of zones or sub-pictures.

Figure 11 is an elevation of a mask which is used for forming the zonesshown in Figure lo Fisure 12 is an elevation of one of a first ofstereoscopic negatives. This is Ellgllfid her. aontally with slots and85cc of the r" shown in Figure Ill and with Zones and 0; Figure to showthat said slots are use produce said zones. This figure also shows thenegative aligned with slots H59 and 6159s or the mask.

Figure 13 is an elevation of the second of said first pair oistereoscopic negatives shown hoi-i= zontally aligned with slots ltd andlfiitla and with Figure 10 to show that said slots are used to pro-Figure 15 is an elevation showing a film which is projected bycontinuous longitudinal movement, and the cylinders in the date. Thearrow shows that the cylinders are reciprocated in a horizontal line.

Figure 16 illustrates how the zones are printed on the home 0! Figures10 and 15.

aasaeao Figure 17 shows diagrammatically the scan-- ning and projectionsystem.

figure 18 is an elevation of the battery of cyl inders which is usedwith the mash oi Figure designated by the reference numerals l Theseframes are stereoscopic views of the same object, the frame 11, for erole, corresponding to a left-eye View and the e corresponding to aright-eye view. Said es E and 2 can be taken in consecutive ore.nultaneously, by means of a stereoscopic ca... .a or the usual type.

Fig. 2 shows how the frames 5 and 2 have been reduced in height, andwithout reducing their width. The frame EA. corresponds to the reducedframe i, and the frame 2A corresponds to the reduced frame 2.

Fig. 2 also shows how the reduced frame Ml has been divided into asuitable series of imaginary optical sections lo, la, and M, the reducedframe M. has been divided u o the same number of imaginary opticalsections 26, 2f, 29, and

Fig. 3 shows a composite f ame which been made by assembling in eoptical sections of the trarr example, the top section o trated in Fig.3. is the top sec m. L

2A.. r'ra The next section of t is the top section 2c of the sem'oiingthese sections of t of the right-eye frame, a c be made, said frame consare respectively left-eye The manufacture of the type illustrated inmeans of well known o fore require no further have described an. provecans for producii'ig such a or herein. shows of n illustrated on 2; ofthe optical axis of a cyli l'iie optical axis of t to the axis of theoptic "nt 2i, and said optical located c between the too edge and thelzottom of the frame section 2?. Fig. 4 also shows the li ht area whichli lustrates the magnification of the height of the optical section 2f.As is well known, a cylinder magnifies only one dimension of the objectwhich is viewed through the cylinder or which is pro= looted by means ofthe cylinder and therefore 4 illustrates how the frame section 2 hasbeen magnified only along one of its dimensions, namely, its heigh Fig.5 illustrates how light is projected by means of any suitable deviceupon the film 3, and how the light which passes through theopticalsection 2; is caused to pass through the cylinder 0, so as to form animage, which may be real or virtual. The real image may be formed withinthe cylinder C, although the invention is not to be restricted to this.Fig. 5 also illustrates a conventional objective or projecting lenssystem 5, by means of which an enlarged image of the section 2f isprojected upon the screen S.

In this embodiment thecylinder C magnifies the section if. so as tocompensate for the reduction in height of the'original frame 2. In otherwords, assuming that the frame IA is onehalf the height of the frame I,and the frame 2A 11 theresatisfactory .osite frame.

8, which has e optical secy aligned with der C is parallel is one-halfthe height of the frame 2. the cylinder C, in such case, would magnifythe height of the frame segment 2!, to twice the height of said framesegment. The magnified image of the frame segment If is then projectedin the usual manner.

It will be noted that the cylinder C will project the frame section 21,only when the optical axis of the cylinder C is located substantiallyintermediate the top edge and the bottom edge of said frame section 2f.Therefore, if the cylinder C is moved up and down rapidly, while thefilm or frame I is held stationary, the movement of the cylinder C willcause the successive projections of the various sections la to 2h. Thediameter of the end faces of the cylinder C is greater and may be muchgreater than the height of a frame section. Therefore, and as-previouslyexplained, the relative movement between the cylinder C and the sectionsof the composite monostereoscopic frame 3, would cause said framesections to be projected one by one upon the screen. By employing abattery or assembly of cylinders,

as later described herein, alternate frame sec-' tions of the typeillustrated in Fig. 3 are projected upon the screen, while theintermediate sections are not projected. Hence a sufliciently rapidmovement of the cylinder C will give the effect of monostereoscopicvision, by reason of the alternate projection of series of alternatesections of the frame.

Figs. 6 and '7 illustrate the assembly of a plurality of cylinders C.Each of these cylinders C has an axial length, which is less than thediameter ofthe end face of said cylinder. These cylinders C are arrangedin echelon, as illustrated in Fig. '7. Fig. '7 indicates, in brokenlines, a rectangle 5, in order to indicate the general dimensions andthe arrangement of the assembly of cylinders C. Fig. '7 also shows theframe 3, in proper relative relation to the assembly or battery ofcylinders C. Fig. '7 also illustrates, by means of the double-headedarrow, how the cylinders are moved parallel to their axes. In Fig. '7,the optical sections of the frame 3 are located horizontally, in thesame manner illustrated in Fig. 3. Fig. 7 therefore illustrates how thebattery of cylinders C, when they are reciprocated, rapidly scan theoptical segments, so that at any given time, only a part of each opticalsegment is being projected. When the projection of one optical segmenthas been terminated, a part of the succeeding optical section is stillbeing scanned or projected. A

As previously noted, each cylinder projects only the frame section whichis aligned with the thickest part of the cylinder.

The top left-hand cylinder in Fig. 7, projects is reciprocated withsuitable rapidity in a vertical up and down direction. The same opticaleffect previously mentioned is secured, because the frame is projectedat any given interval only in sections,'each section corresponding tothat part of the frame which is substantially aligned with the opticalaxis of one of the cylinders C.

only the adjacent part of the top frame-sectionf The next cylinder onlyprojects the frame-section below the top frame section, etc. Thecylinders can be located and reciprocated so that a part of eachframe-section is always being projected. Whenever the cylinders are-usedto project frame-sections, an objective "lens can be utilized for thefinal projection.

Figs. 8 and 8a illustrate the frame 3, and a battery of cylinders C,which are arranged in superposed relation, so that the horizontal axesof the cylinders are in the same vertical plane. For the purposes ofthese figures, it is assumed that the film of which the frame 3 forms apart, is intermittently fed in a downward vertical direction. As shownby the double-headed arrows in Fig. 8 and in Fig. 8a, the battery of ,Qllnders,

It will be noted that the cylinders shown in Fig. l and in Fig. 8 canbe'used with an ordinary motion picture film taken by means of theconventional camera and in the conventional manner.

Figs. 9 and 9a are leased on the same principle as Figs. 8 and 8a. InFigs. 9 and 9a, and as shown by the double headed arrow of Fig. 9a,

the battery of cylinders which is shown in Fig. 8

is arranged with their axes vertical, and said battery of cylinders isreciprocated with sufficient rapidity, in a horizontal direction.

This method can be used with ordinary motlon picture film or with a filmhaving the special type of composite stereoscopic frame which haspreviously been disclosed. However, if the method illustrated in Figs. 9and 9a is utilized in connection with a film having frames of the typeof the frame 3, the optical sections of such frame would then be heldvertically, instead of being held horizontally as shown inFig. 3.Likewise, in utilizing a frame with the method shown in Figs. 9 and 9a,the width of the frames i and 2 would be reduced, leaving then-heightunchanged.

The optical principles disclosed herein, make it possible to produce amotion picture positive film, which can be fed continuously through aprojector, instead of using the intermittent feeding and the shutter,which are now conventional. It is highly desirable to be able to feedthe positive film continuously through the projector, since greaterillumination can be secured, there is less'wear on the film, and thequality of the projection is improved;

The general principle is illustrated in connectlon with Figs. 10-17.

Fig. ll shows a mask having slots which are arranged in lateral rows.spective lateral rows are offset relative to the slots of the precedingrow and of the succeeding row.

For example, let it be assumed that it is desired to make amonostereoscopic film from pairs of stereoscopic negatives. One pair ofstereoscoplc negatives is shown in Figs. 12 and 13 and a stereoscopicnegative of the next pair is shown in Fig. 14. It can be assumed thatthe first stereoscopic negative shown in Fig. 12 has the top part of themask shown in Fig. 11 applied thereto, so that the slots I58 and mm ofsaid mask expose two separated vertical zones of the first stereoscopicnegative. Each of the slots I58 and I5la has an area which is equal toonefourth the area of the stereoscopic negative of Fig. 12. Hence thetotal area exposed by the ,slots I58 and I580 is one-half the total areaof The slots of the rein full height. The vertical zone [155a which hasbeen photographed upon the positive, likewise .corresponds to that partof the negative which The same first stereoscopic negative of Fig. 12

is now subjected to a. second exposure, with the use of slots I59 andI59a, and in this second exposure the remaining one-half of the totalarea of said first stereoscopic negative is exposed, so as to producelaterally reduced vertical zones I55b and I55c, as shown in Fig. 10. Thefour separated vertical zones which thus correspond to the entire firststereoscopic negative are 'all recorded upon the same frame of thepositive, so that the tops and bottoms of zones I55 and I55a, I55b andI550, are located on two paralled horizontal lines. 01' course when theslots I59 and I55a are utilized, the cylinders which are utilized areshifted or adjusted so as to be properly aligned with said slots I59 andI59a.

Since stereoscopic negatives come in pairs, the next operation is toprint the second stereoscopic negative of said first pair, this secondstereoscopic negative being shown in Fig. 13.

ThlSLlSQODE in a similar sequence of operations.

For example, in the first exposure of the second stereoscopic negativeof said pair, I use the slots 665 and Ifita of the mask, so as tophotographically print the reduced vertical zones i155 and I56d, on thesame irame or lateral portion of the positive, upon which the verticalzones 855-6550 inclusive, have previously been photographed. The secondstereoscopic negative is then again photographed, using slots i5! andMia, and it may be assumed that in the second exposure, the secondstereoscopic negative is in the position shown in Fig. 13.

Likewise a third stereoscopic negative, shown in Fig. 14, and belongingto the next pair of stereoscopic frames, can be photographed upon thesame frame oi the positive film, by recording the zones i517, 215M, itlhand Milo. This stereoscopic negative oi the second pair, is shown in twopositions in Figli i. Fig. it therefore shows a monostereoscopic frameoi a positive, upon which three stereoscopic negatives have beenrecorded.

As shown inFig, it, if it desired to make a positive film which can hefed continuously, the zones i155 and i55o and and i55c are locatedacsacze.

level; below the zones I-I55c', inclusive, as shown in Fig. 15.

According to the scale used in this illustrative example. the entirewidth of the positive film is occupied by twelve of these zones.

Hence, as shown in Fig. 15 when the fourth stereoscopic frame isrecorded upon the positive film, said forth stereoscopic frame isrecorded by means of four zones, and these four zones are locatedunderneath and they are aligned with the four zones I55, I55a, I55b andI550. One of these four zones is indicated by the reference numeral I55in Fig. 15.

This process -is then continued so as to photograph any desired numberof stereoscopic negatives consecutively upon the positive film shown inFig. 15. Fig. 16 show how the light can be passed through the sin ofmask I15, then through the negative film N, then through cylinderslocated in an opening of an opaque holder, and how the light is thenallowed to fell upon the light-sensitive positive film P.

In projecting a positive film of the type shown in Fig. 15, the light iscaused to pass through said positive film, then through a batteryoLenlarging cylinders, as illustrated at the bottom of Fig. 15, and thenthrough the objective lens system. The enlarging cylinders shown in Fig.15 can be moved back and forth very slowly and through a short distancealong a horizontal line,

while the film is being fed continuously in a vertical line, at asuitable slow speed.

The cylinders will simultaneously scan and ened to project saidsub-pictures I55, I550, I551),

l55c, etc.

During the projection, the cylinders enlarge the zones, anterior to theobjective lens system,

- so as to produce a. continuous positive duplicate at the same level onthe positive film. This being on the same level. This is shown in Fig.

The positive film is now shifted through the gate to a distance equal tothe distance of the first shift, and the four zones I5'i, I5la, and

I i511) and I5lc are now printed upon the same of the original negativeframe.

In printing the laterally reduced zones on the positive, it is necessaryto have cylinders of sufficiently large diameter to pick up thefull-sized zones of the stereoscopic negative. For example, thewidth ofthe film may be one inch, so that the width of a zone of the negativestereoscopic frame is 0.25 inch. In orderto photograph and reduce thiszone, the diameter of the cylinder must materially exceed 0.25 inch.

In projecting the reduced zone, it is possible and preferable tolaterally enlarge the reduced zone to its original width of 0.25 inch,by using a cylinder located as close as possible to the reduced zoneE55, etc. This makes it possible to use cylinders during the Projection,of much smaller diameter than the cylinders used to print the zones ofthe negative on a laterally reduced scale. This is preferable, in orderto project a continuous duplicate of the original frame, during themovement of the projecting cylinders.

During the projection of the positive film, the movement of theprojecting cylinders may be in r synchronism or it need not be insynchronism with the continuous slow movement of the positive film. Ifsynchronism is desired, said cylinders should first project the fourzones which correspond to the first stereoscopicframe, and then projectthe next set of four zones which corre-' spond to the secondstereoscopic frame, and so on. As shown in Fig. 15, the width of areduced zone is less than the distance between two reduced zones in thesame lateral row.

If it is desired to. make a positive of a nonstereoscopic type which canbe run continously through the projector, the same procedure is followedin copying the consecutive frames of a non-stereoscopic negative, saidnegative being of the ordinary type which is taken by means of anordinary camera, using a single lens.

If a positive film of the type which is run continuously and slowlythrough the projector is being utilized, said film may become overheatedby the light source. Therefore, during the projection of the film, I canuse a mask of the type shown in Fig. 11, so as to expose to the light,only those zones of the positive film which are to be projected at theparticular time. The slits in said projecting mask can correspond inwidth to the width of the laterally reduced zones on the positive film.

Fig. 17 diagrammaticallyillustrates how the source of light can beshifted while the cylinders are scanning the continuously moving film ofthe type which is shown in Fig. 15. In Fig. 1'? it is assumed that thefilm is being fed downwardly and in a direction perpendicular to theplane of the paper and the arrow indicates the scanning movement of thecylinders in one direction. The cylinders will be moved back and forthalong the direction line which is indicated by said arrow.

In this embodiment the direction of the light which is transmittedthrough the film. is also changed, so that the effect is the same asthough the source of light were moved to and fro along a horizontalline, the light being moved in the same direction as the cylinders. Thatis, when the cylinders are being moved towards the head of the arrowindicated in Fig. 1'7, the source of light is moved in the samedirection. The zones indicated in Fig. 15 may be so narrow as to producean effect similar to the pinhole effect, so that the light falls uponthe scanning cylinder, along a direction line which is drawn between thesource of light and the central point of the zone.

That is, Fig. 15 shows that a negative frame is represented by the fourzones E55, I55a, I55b,

and I550, and these zones are narrow and the space between each pair ofsaid zones greatly exceeds the width of each of said zones.

In Fig. 15-the spaces between the zones I55, I55a, I552) and I55c aresubstantially transparent, because said spaces have not been exposed.

Referring to Fig. 17, the source of light is in the position indicatedby the reference numeral I55L, when the scanning cylinder is in theposition indicated by I55L.

Fig. 17 shows the direction of the light from the source I55L to thecentral line of the zone I55b. The cylinder in the position I55L' formsin effect, an image of the zone I55b along the zone which is indicatedby the heavy black line of the cylinder in the position I55L.

7 As the cylinder moves from the position indicated by 1551- to theposition indicated by I56L', the source of light is moved from theposition I55L to the position shown in I56L.

The result is to form, in effect, an image of the. zone I58bcorresponding to the portion of the cylinder in the position I56L',which is indicated by the heavy black line.

The same result follows when the source of light is moved to theposition I 51L and the scanning cylinder has been moved to the positionIS'IL'.

The effect is to maintain the image in the same position relative to theobjective lens system which is indicated by the reference letter 0 inFig. 17. The image in effect turns about a fixed central point which ison the optical axis of the objective lens system 0.

Hence as consecutive corresponding zones are scanned, they will beprojected upon the same part on the motion picture screen. For example,the zones I55 and W6 and it?! will each be projected upon the sameportion of the screen. Likewise the zones I55 11, Etta, and this, willbe consecutively projected upon the same part on the motion picturescreen, this part being diiferent from the part which receives theprojections of the zones I55, W6 and 853i.

Hence the picture which is projected upon the motion picture screen willnot be shifted upon said screen thus eliminating disagreeable flickeringand the like. 1

Whenever I refer to the use of a cylinder, I include, as an equivalent,a segment of a'cylinder, or a thick lens of any type, in which thethickness of the lens is sufficient to determine the nature of therefraction, and to determine the area of the picture which is beingscanned.

That is, the ordinary lens is so thin, and it is so free from sphericalaberration, so that the area of the picture which is being scanned, issubstantially equal to the entire area of the lens.

According to my method, I scan separated parts of the frame or picture,without the use of slitted screens which would provide sharply definedlights and shadows, and cylindrical lenses are only one of the numerousretracting or reflecting means which would accomplish this purpose.

I claim: I

1. A method of producing stereoscopic projection of motion pictures withthe use of a single film which is moved intermittently in apredetermined longitudinal direction so as to successively andintermittently project successive frames of said film, which consists inphoto-,

graphically printing in each frame at least two series of sub-picturesin a row which is lateral to said direction by separating continuousnegatives respectively into spaced sub-pictures of less while the filmis stationary so as to project the respective series successively in theform of continuous projected pictures, said lateral scanning beingsufiiciently rapid to give the effect of persistence of vision.

' 2. In the art of producing stereoscopic projection of motion picturefilms with the use of a single film which is moved intermittently in apredetermined longitudinal direction so as to successively andintermittently project successive frames of said film, which consists inphotographically printing in each frame at least one pair of pictures ofa moving object in the same position and. taken at different anglesinlateral scanning while the film is at rest, said dependently of themovement of said. object rel= successive scanning and projection beingsumatlve to the means of taking said pictures, by clently rapid to givethe effect of persistence of printing negatives while xeduclng theirwidth, vlslon.

said pair of pictures being located in a lateral 5 row, and projectingsaid pictures successively by JACOB Z. DENINSON.

